Need algebra help with 2 x 2 system or linear equations that are inconsistent or consistent dependent

First, we need to add algebraically both equations. We add all what we have on the left side of each equation equal to the addition of all what we have on the right side of each equation. So we would have:

So again, as we can see all the x's and y's cancel out leaving a true equality (- 5 = - 5). So when this happens then it means that the system has infinitely many solutions. After this, we just need to choose the 1st r 2nd equation and we solve for y like this.